Door sill

ABSTRACT

Door sill includes a substrate or base member of wood or other insulating material having a metal sill cover secured to the exterior projecting portion of the substrate and terminating adjacent the exterior side of the door when in the closed position, and having a rigid vinyl thermal barrier member connected to the substrate directly beneath the door when in the closed position as by means of downwardly projecting ribs which extend into grooves in the substrate. A sealing strip on the bottom of the door provides sealing contact with the rigid vinyl member when the door is in the closed position.

United States Patent Coppins June 6, 1972 DOOR SILL Primary Examiner-David J. Williamowsky [72] Inventor' g;:3 g; g :l Faith! Road Assistant ExaminerPhilip C. Kannan Anorney0berlin, Maky, Donnelly & Renner [22] Filed: June 19, 1969 k 21 Appl. No.: 834,674 [57] ABSIRACT [52] U.S. Cl ..49/469 Door sill includes a substrate or base member of wood or other insulating material having a metal sill cover secured to the exterior projecting portion of the substrate and terminating adjacent the exterior side of the door when in the closed position, and having a rigid vinyl thermal barrier member connected to the substrate directly beneath the door when in the closed position as by means of downwardly projecting ribs which extend into grooves in the substrate. A sealing strip on the bottom of the door provides sealing contact with the rigid vinyl member when the door is in the closed position.

7 Claims, 4 Drawing Figures l l7 16 l 23 1 PATENTEDJun 6 I972 DOOR SILL BACKGROUND OF THE INVENTION The present invention relates generally as indicated to a door sill, primarily for use with exterior doors, including a thermal barrier member for substantially eliminating the transfer of heat between the exterior and interior and thereby preventing the buildup of frost and condensation.

Most modern day door sills for exterior doors have metal portions which provide greater wear and longer, relatively SUMMARY OF THE INVENTION With the foregoing in mind, it is a principal object of this invention to provide a door sill construction including a thermal barrier which is relatively simple and inexpensive in construction and is easily installed.

Another object is to provide such a door sill which has relatively few parts that can readily be assembled and disassembled when required.

A further object is to provide such a door sill which has a relatively long, substantially maintenance-free life.

These and other objects of the present invention may be achieved by providing a door sill construction with a wood or likesubstrate having an exterior projection to which is secured a metal sill cover that tenninates adjacent the exterior side of the door when in the closed position. Directly beneath the closed door is provided a rigid vinyl or other insulating material which has downwardly projecting ribs that extend into grooves or notches in the wood substrate for securing the member in place. A sealing strip may be provided on the bottom of the door for establishing sealing contact with the rigid member when the door is closed.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of a few of .the various ways in which the principles of the invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawings:

FIG. 1 is a fragmentary isometric view of a preferred form of door sill construction in accordance with this invention shown installed in a typical door frame in which the door is mounted for inward swinging movement;

FIG. 2 is an enlarged fragmentary longitudinal section through the door sill of FIG. 1;

P16. 3 is a longitudinal section through another form of door sill in accordance with this invention particularly for use with outswinging doors, and

FIG. 4 is a fragmentary longitudinal section through a modified form of door sill in accordance with this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawings and first especially to FIGS. 1 and 2, a preferred form of door sill l is shown installed across the bottom 2 of doorway 3 which may be of standard type including a frame 4 to which is secured a door stop 5 for locating the door 6 in the closed position. The door 6 may also be of any well known construction and hung in conventional manner. Either wood or metal may be used for the door, but if metal is used, a thermal break or gap 7 is desirably provided between the metal door facings as shown in FIG. 2 to reduce transfer of heat from one side of the door to the other and thereby eliminate condensation and frosting. Magnetic weather strip 8 may also be secured along the entire length of the door stop 5 to provide a positive seal with the metal door 6 when closed.

As illustrated, the door sill l is somewhat exaggerated in size in relation to the door and door frame to permit a more clear showing of the details thereof. However, it should be understood that the maximum vertical dimension of the door sill is relatively small, in the order of l to l inches, so as not to provide an obstruction to persons passing through the door way. In any event, such door sill 1 includes a substrate or base member 10 of wood or other insulating material having a tapered exterior projecting portion 11 extending outwardly beyond the exterior side of the door 6 when closed and a flat threshold portion 12 directly beneath the door when closed. Secured to the exterior projecting portion 11 is a metal sill cover 13 which terminates adjacent the threshold portion 12 and secured to the threshold portion 12 is a thermal insulating member 14 of rigid vinyl plastic (i.e., polyvinyl chloride) or other suitable plastic or other insulating material. When the door 6 is of the inswinging type illustrated in FIGS. 1 and 2, the base member 10 desirably terminates adjacent the interior side of the door as shown, whereas when the door 6 is mounted for outward swinging movement as in FIG. 3, the base member 10' desirably includes an interior projecting portion 15 which extends inwardly beyond the interior side of the door and tapers downwardly at a slight angle to avoid tripping over the door sill from the inside.

Whether the base member 10 terminates adjacent the interior side of the door or extends inwardly therebeyond, the bottom face 16 thereof is desirably flat for direct mating engagement with the flat exterior surface 17 of the floor 18, which may be a concrete slab, wood, or other material, and the base member 10 is secured in place using fasteners or a suitable adhesive. The sill cover 13 is of heavy gauge aluminum or other suitable material which resists wear and has a relatively long maintenance-free life even when exposed to severe weather year around. Transverse grooves 19 may be provided in the upper surface of the sill cover 13 to provide a non-skid surface. Otherwise, the sill cover 13 is substantially flat for direct engagement with the upper tapered surface 20 of the exterior projecting portion 11 of the base member 10 except for the forward end 21 of the sill cover 13 which is turned downwardly for engagement with the forward end 22 of the base member 10 and the rear end 23 of the sill cover 13 which projects upwardly adjacent the exterior side of the door 6 when closed to provide support for the forward edge of the thermal barrier member 14, in a manner to be subsequently described.

The sill cover 13 may overlie the forward end of the flat threshold portion 12 of the base member 10 as shown in FIGS.

1 and 2, in which event the rear end 23 of the sill cover also.

desirably projects slightly downwardly to provide support for that end of the sill cover, or alternatively a step 25 may be provided in the upper surface of the base member 10' between the exterior projecting portion 11' and threshold portion 12' to provide adequate support for the rear end 23 of the sill cover 13' as shown in FIG. 3. Suitable fasteners such as carbon tip staples or adhesive may be used to secure the sill cover 13 to the base member 10, and the door stop 5 which engages the top of the sill cover 13 also aids in holding the same in place.

The thermal barrier member 14 is located in position beneath the door 6 when closed as aforesaid and is desirably made of a relatively rigid plastic such as rigid vinyl which may be extruded into the desired shape. Although the cross-sectional configuration of the member 14 may vary somewhat, the body portion 27 thereof is substantially flat and has a plurality of ribs 28, 29 and 30 projecting downwardly therefrom into grooves or notches 31, 32 and 33 in the base member 10 as shown in FIGS. 1 and 2 for securing the member 14 in place. The sides of the intermediate groove 32 are desirably vertical and are contacted by an enlargement 34 on the lower end of the rib 29, whereas one of the walls (the opposite walls) of the end grooves 31 and 33 may have a reverse slope with the wider part of the grooves at the bottom to prevent direct upward movement of the enlargements 35 and 36 on the lower ends of the ribs 28 and 30. The other walls of the grooves 31 and 32 may be vertical. I

Altematively, one or more of the ribs 30' may be of a length shorter than the ribs 28 and 29' for supporting the body portion 27"of the thermal barrier member 14' on the upper surface of the base member forwardly of the ribs 28' as shown in FIG. 3, and the forward end of the thermal barrier member 14 or 14extends beyond the upwardly projecting rear end portion 23 or 23 of the sill cover 13 or 13' for support thereby and has a downtumed lip 39 or 39 forwardly of such rear end portion to provide a water seal between the sillcover and thermal barrier member. Moreover, onegor more of the ribs 28, 29' or 30' may have upwardly projecting barbs 37 thereon for engagement with the vertical sides of the grooves 31 32 and 33' to resist pull-out, as shown in FIG. 4. Otherwise, the door sills of FIGS. 3 and 4 aresubstantially identical to that shown in FIGS. 1 and 2, and the same reference numerals followed by a prime symbol are used to designate like parts.

To assemble the thermal barrier 14of FIGS. 1 and 2 and 14' of FIGS. 3 and 4 onto the base member 10 or 10, the enlargements or barbs on the ends of the ribs are snapped into their respective grooves in the base member, which may be done prior to or after securing the base member in place.

When properly assembled, the door 1 or 1' effectively prevents a buildup of frost and condensation on either side of the door since the metal sill cover 13 or 13' terminates short of the interior side of the door when closed, and the rigid vinyl member 14 or 14' provides a thermal barrier preventing transfer of heat from one side of the door to the other. A slight clearance on the order of one-eighth inch is provided between the bottom of the door and the thermal barrier member 14 or 14' so as to eliminate interference of the door with the rigid vinyl member during closing of the door, which clearance is taken up by'a resilient positive vinyldoor seal 43 on the bottom of the door.

From the foregoing, it can now be seen that the various door sill constructions disclosed herein are of a relatively simple and inexpensive construction including only three components which may be readily assembled without the need for special tools, and one of the components provides a thermal barrier beneath the door preventing buildup of frost and condensation despite substantial terperature differentials between the exterior and interior. Moreover, in case of damage, the plastic thermal barrier member is easily replaceable.

, I, therefore, particularly point out and distinctly claim as my invention: 7

l. A door sill comprising a base member of insulating material adapted to be secured to the threshold of a door frame, said base member including a threshold portion for disposition directly beneath the door supported in such frame when such door is in the closed position, and an exterior portion for extension outwardly beyond the door when closed, a sill cover of metal secured to said exterior portion of said base member, said sill cover terminating adjacent the exterior end of said threshold portion, and a rigid thermal barrier member of insulating material secured directly to said threshold portion to prevent a transfer of heat between said metalsill cover and thermal barrier member, said thermal barrier member including a substantially flat body portion having three ribs projecting downwardly therefrom for supporting said thermal barrier member on said base member, said threshold portion having three grooves therein for receipt of said ribs, said ribs having enlargements on the lower ends thereof received in said grooves, two of said grooves having one of their walls which are opposite each other of a reverse slope and their other walls vertical so that the wider part of said two grooves is atthe bottom preventing direct upward movement of the associated ribs from said two grooves.

2. The door sill of claim 1 wherein both walls of the third groove are vertical.

3. The door sill of claim 1 wherein said sill cover has an upwardly projecting rear end portion and the forward end of said body portion extends over said upwardly projecting rear end portion for support thereby.

4. The door sill of claim 3 wherein the forward end of said body portion has a down-tumed lip forwardly of the upwardly projecting rear end portion of said sill cover.

5. The door sill of claim 1 wherein said thermal barrier is made of a rigid vinyl plastic and said sill cover is aluminum.

6. The door sill of claim 1 wherein said threshold portion is substantially flat and said exterior portion is tapered, said sill cover intermediate its ends having direct mating engagement with said exterior portion, the forward end of said sill cover being turned downwardly for engagement with the forward end of said exterior portion of said base member, and the rear end of said sill cover overlying the forward end of said threshold portion, said rear end of said sill cover projecting downwardly to provide support therefor.

7. The door sill of claim 1 wherein said threshold portion is substantially flat and said exterior portion is tapered, said sill cover intermediate its ends having direct mating engagement with said exterior portion, the forward end of said sill cover being turned downwardly for engagement with the forward end of said exterior portion of said base member, and the rear end of said sill cover projecting upwardly to provide support for the forward end of said thermal barrier member, said base member having a step between said exterior portion and threshold portion providing support for said rear end of said sill cover. I 

1. A door sill comprising a base member of insulating material adapted to be secured to the threshold of a door frame, said base member including a threshold portion for disposition directly beneath the door supported in such frame when such door is in the closed position, and an exterior portion for extension outwardly beyond the door when closed, a sill cover of metal secured to said exterior portion of said base member, said sill cover terminating adjacent the exterior end of said threshold portion, and a rigid thermal barrier member of insulating material secured directly to said threshold portion to prevent a transfer of heat between said metal sill cover and thermal barrier member, said thermal barrier member including a substantially flat body portion having three ribs projecting downwardly therefrom for supporting said thermal barrier member on said base member, said threshold portion having three grooves therein for receipt of said ribs, said ribs having enlargements on the lower ends thereof received in said grooves, two of said grooves having one of their walls which are opposite each other of a reverse slope and their other walls vertical so that the wider part of said two grooves is at the bottom preventing direct upward movement of the associated ribs from said two grooves.
 2. The door sill of claim 1 wherein both walls of the third groove are vertical.
 3. The door sill of claim 1 wherein said sill cover has an upwardly projecting rear end portion and the forward end of said body portion extends over said upwardly projecting rear end portion for support thereby.
 4. The door sill of claim 3 wherein the forward end of said body portion has a down-turned lip forwardly of the upwardly projecting rear end portion of said sill cover.
 5. The door sill of claim 1 wherein said thermal barrier is made of a rigid vinyl plastic and said sill cover is aluminum.
 6. The door sill of claim 1 wherein said threshold portion is substantially flat and said exterior portion is tapered, said sill cover intermediate its ends having direct mating engagement with said exterior portion, the forward end of said sill cover being turned downwardly for engagement with the forward end of said exterior portion of said base member, and the rear end of said sill cover overlying the forward end of said threshold portion, said rear end of said sill cover projecting downwardly to provide support therefor.
 7. The door sill of claim 1 wherein said threshold portion is substantially flat and said exterior portion is tapered, said sill cover intermediate its ends having direct mating engagement with said exterior portion, the forward end of said sill cover being turned downwardly for engagement with the forward end of said exterior portion of said base member, and the rear end of said sill cover projecting upwardly to provide support for the forward end of said thermal barrier member, said base member having a step between said exterior portion and threshold portion providing support for said rear end of said sill cover. 